registry: Import gl.xml from Khronos registry

Import revision 26792 on 2014-05-22 from
(https://cvs.khronos.org/svn/repos/ogl/trunk/doc/registry/public/api/gl.xml).

I want to generate piglit-dispatch code from the official Khronos XML
rather than scraping GL headers and unmaintained *.spec files.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
WIP dispatch: Generate from Khronos XML

TODO: Test for regressions
TODO: Commit message
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
WIP: util: Generate enum stuff
more enum
WIP glapi: Remove unused files

TODO: Test
TODO: Commit message
WIP dispatch: Rename files

TODO: Commit message
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>